The Illinois Pollution Control Board holds hearings this week about construction debris rules proposed by the state Environmental Protection Agency. The hearings are focused on whether dirt and debris from construction and demolition sites is clean enough to be deposited in quarries. State statutes mandate that the deposits be clean, but “clean” has never been clearly defined.

(http://www.nytimes.com/2011/09/23/us/rules-for-identifying-clean-dirt-to-be-considered.html)